Electric pick-up device



Dec. 8, 1931. s. MCCLATCHIE ELECTRIC PICK-UP DEVICE Filed Dec. 5, 1929 RO T m V Nu stahleg mc Clahzhie W W RTTORHEY,

Patented Dec. 8, 1931 UNITED. STATES STANLEY MCGLA'IGHIE, onvBERLIN-wImvrnnsnonr, GERMANY ELECTRIC PICK-UP DEVICE Application filedDecember 3, 1929, Serial No. 411,317,:and in Germany August 8, 1929.

This invention relates to electric pick-up devices, and is moreparticularly concerned with magnetic sound pick-up devices such as areused in phonographs for reproduction'of 6 sound or speech recorded upona phonograph record. 7 v

The first object of the invention is to provide a sound box or pick-upfor a phonograph with an oscillating magnetic armature of minimumweight, wherebya faithfulreproduction of the sound is obtained.

Another object of the invention is to provide a pick-up device for aphonograph which is of small cost.

Another object of the invention is to provide means in connection-withan electric" pick-up device for phonographs and the like by which thelife of the records as well as the needles-may be increased.

Still another object is to provide apick-up device which enables a readyand easy replacement of a used needle.

The variousfeatures and further objects of my invention will becomeapparent as the following detailed description proceeds, with referenceto the accompanying drawings. I wish it to be understood that thespecific embodiment of my invention as illustrated by the drawings isillustrative only of the novel idea underlying my invention and shouldnot have the effect of allowing a narrow interpretation of theinvention, short of its broad scope as expressed by the terms of theappended claims. Similar reference numbers refer to similar elementsthroughout the different views of the drawings.

Figure 1 of the drawings shows in cross-section a sound boX inaccordance with my in vention taken along the section line I-I of Figure2. r

' Figure 2 is a section taken along line IIII of Figure 1. V

Figure 3 shows a longitudinal section taken along section line IIIIII ofFigure 2.

According to the invention, the pickup armature is provided with aflange held between damping surfaces of rubber or similar resilientmaterial. r V V The armature may have different forms.

which is easy and simple to manufacture and According to a preferredembodiment of the invention, the armature has the form of a metal tubefor receiving the phonograph needle. This tube is provided at one. endwith a flange held between gaskets of cushioningor damping material. Inthis embodiment, the needle is held in a simple manner merely by theoblique pressure of the pick-up, whichforces the needle angularly intoopposing V-shaped portions of the tube. This con-. struction eliminatesthe necessity for a clamp ing screw and the necessary guiding elementstherefor, and results in a further reduction of the weight of theoscillating mass.

Referring to the drawings, afield magnet 1 (only partially shown) isarranged within a casing 2. This magnet is provided with pole pieces 4which are mounted on an interme diate wall 6 between the main casing 2and a detachable cup-shaped lower casing 7. 5 is the spool for the coil3. The cup 7 is attached to casing 2 by screws 9 and 10, with aresilient gasket 8, and the spool flange 8 interposed. a

The armature 11 is in the form of an iron 7 sleeve and is provided atits lower end, with a flange or ring-shaped extension 12 which isresiliently mounted between andheld in position by resilient gaskets 13and 1 1.- The armature tube 11 has preferably a rhomboidalcross-section, as shown at 11 in Figure 2. In operation, the needle isforced by the weight of the pick-up into a slightly oblique positionwithin the armature tube, and is thuswedged into firm engagement withthe armature without the use of a retaining screw. This con struction isvery simple in itself, simplifies the interchangeof needles and relievesthe armature of the undesirable additional weight of a set-screw withaccompanyingretaining walls. The needle is prevented from falling outwhen the pick-up does not rest on the recordeither by friction at themouth of-the gasket 14, or by the inherent magnetic at? traction of thearmature. The gaskets 13, 14:, together with a washer 17 and cover-plate17' are fastened together and connected to the lower wall of thecup-shaped casing part 7 by means of rivets 16. The gasket 8 between thelower part 7 of the casing and the intermediate wall 6 serves to allowthe adjustment of the armature between the pole pieces 4 by means of theset-screw 10.

Although the invention has been specifically described in reference tothe showing of the drawings, it is obvious that it may be applied inother ways.

\Vhat I claim is:

1. A sound reproducing device for phonographs and the like, comprisingin combina tion, a supporting member, an armature adapted to engage astylus, a supporting flange on said armature, and a resilient cushioncarried by said supporting member and engaging the armature-flange so asto support the armature and at the same time damp oscillations of thesame.

2. A sound reproducing device for phonographs and the like, comprisingin combination, a supporting member, resilient gaskets held by saidmember, a tubular armature adapted to engage a stylus, and a flange onsaid armature which is clamped between the said gaskets in such manneras to support the armature and to damp oscillations.

3. In an electro-magnetic sound reproducing device for phonographs andthe like, comprising in combination, a casing structure, a magnetassociated with said structure, pole pieces for said magnet, aphonograph needle to be subjected to mechanical oscillationscorresponding to the oscillations of sound to be reproduced, a sleeve ofmagnetic material for holding said needle arranged between said polepieces and serving as the armature of said pick-up device, a flange ofsaid sleeve and means for elastically mounting said sleeve, said meansconsisting of sheets of elastic material carried by said casingstructure, said flange being clamped between said sheets.

4. In an electro-magnetic sound reproducing pick-up device forphonographs and the like comprising in combination, a casing structure,a magnet associated with said casing, pole pieces of said magnet, aphonograph needle to be subjected to mechanical oscillationscorresponding to the oscillations of sound to be reproduced, a sleeveelement with an inner cross-section gradually decreasing in two oppositeradial directions until below the thickness of said needle, to hold saidneedle by clamping action, said sleeve being arranged between said polepieces to serve as operating armature of said pick-up device, a flangeof said sleeve and means elastically mounting said sleeve, said meansconsisting of rubber sheets, fastened together and carried by saidcasing, said flange being clamped between said sheets.

5. In an electro-magnetic sound reproducing pick-up device forphonographs and the like, comprising in combination, a casing structure,a magnet carried by said structure, pole pieces of said magnet, aphonograph needle to be subjected to mechanical oscillationscorresponding to the oscillations of sound to be reproduced, a tube ofmagnetic material squeezed in opposite directions from its center inrespect to its cross-section to an outside width just below thethickness of said needle, so that said needle can be clamped between thecorners of said tube in its operating position, said tube being arrangedbetween said pole pieces to serve as operating armature of said pick-updevice, a flange of said tube and means for elastically mounting saidtube, said means consisting of rubber sheets fastened together andcarried by said casing, said flange being clamped between said sheets.

6. In an electro-magnetic sound reproducing pick-up device forphonographs and the like, as described in claim 5, in which said needleis prevented from falling out of its holding sleeve by means of anelastic lock washer covering the opening of said sleeve.

7. In an electro-magnetic sound reproducing pick-up device forphonographs and the like, as described in claim 6, in which said needleis prevented from falling out of its holding tube by means of an elasticlock washer covering the opening of said tube.

8. In an electro-magnetic sound reproducing pick-up device forphonographs and the like, comprising in combination, a main casingstructure, a magnet carried by said struc ture, pole pieces of saidmagnet, a detachable member of said casing structure, sheets of elasticmaterial held together and carried by said detachable member, aphonograph needle passing through an opening of said sheets, said needlebeing subjected to mechanical oscillations corresponding to theoscillations of sound to be reproduced, means for elastically mountingsaid needle, said means comprising a tube of magnetic mate rialsurrounding and holding said needle by clamping action and arrangedbetween said pole pieces to simultaneously serve as operating armatureof said pick-up device and a flange of said tube, said flange beingclamped between said sheets.

9. In an electro-magnetic sound reproducing pick-up device forphonographs and the like comprising in combination, a main casingstructure, a magnet carried by said casing structure, pole pieces ofsaid magnet, a detachable member of said casing structure, sheets ofrubber held together and carried by said detachable member, a phonographneedle passing through an opening of said sheets, said needle beingsubjected to mechanical oscillations corresponding to the oscillationsof sound to be reproduced, means for elastically mounting said needle,said means comprising a tube of magnetic mate rial arranged between saidpole pieces to serve as an operating armature of said pickup device withan inner cross-section gradually decreasing in two opposite radialdirections until below the thickness of said needle for holding saidneedle by clamping action in its operating position and a flange of saidtube at its lower end, said flange being held in clamping positionbetween said rubber sheets.

10. In an electro-magnetic pick-up device as described in claim 8,wherein said needle is prevented from falling out of its holding tube bymeans of a lock washer of flexible material covering the opening of saidtube.

11. In an electro-magnetic pick-up device, as described in claim 9,wherein said needle r is prevented from falling out of its holding tubeby means of a lock washer of flexible material covering the opening ofsaid tube.

12. In an electro-magnetic sound reproducing phonograph pick-up device,as described in claim 8, in which one of said elastic sheets has aperforation corresponding to the thickness of said needle passing sameto serve as a lock washer for said needle to prevent it from falling outof said tube.

13. In an electro-magnetic sound reproducing phonograph pick-up device,as described in claim 9, in which one of said elastic sheets has aperforation just corresponding to the thickness of said needle passingsame to serve as a lock washer for said needle to pervent it fromfalling out of said tube.

14. In combination with a device transforming mechanical movements intocorresponding magnetic variations, a stylus subjected to said mechanicalmovements, a supporting member, a magnet carried by said member, polepieces of said magnet, a metal sleeve arranged between said pole piecesfor holding said stylus in a clamped position to hold and to serve as anarmature of said magnet, a flange of said sleeve and means forelastically mounting said sleeve, said means including a number ofsheets of wield ing material carried by said member, said flange beingclamped between said sheets.

15. In combination with an arrangement for transforming mechanicalmovements into corresponding magnetic variations, a stylus subjected tosaid mechanical movements, a supporting member, a magnet carried by saidmember, pole pieces of said magnet, a metal tube of magnetic materialarranged between said pole pieces to serve as an armature of said magnetand having an inner cross-section gradually decreasing in two oppositeradial directions until below the thickness of said stylus for holdingsaid stylus in aclamped operating position, a flange of said tube andmeans for elastically mounting said tube, said means including at leasttwo sheets of yielding material carried by said member,

said flange being clamped between said sheets. 7

16. In a pick-up device as described in claim 15, wherein said stylus isprevented from falling out of its holding tube by means of elastic lockwasher covering the opening of said tube.

17. In combination with an arrangement for transforming mechanicalmovements into corresponding magnetic variations, a stylus subjected tosaid mechanical movements, a supporting member, a main casing structure,a magnet carried by said structure, pole pieces of said magnet, adetachable part of said casing structure, sheets of rubber material heldtogether and carried by said detachable part, said phonograph needlepassing through an opening of said sheets, and means for elasticallymounting said needle, said means comprising a tube of magntic materialsurrounding and holding said needle in clamped position and arrangedbetween said pole pieces for simultaneously serving as operatingarmature of said magnet and the flange of said tube, said flange beingclamped between said sheets.

18. In combination with an arrangement for transforming mechanicalmovements into correspondingmagnetic variations, a stylus subjected tosaid mechanical movements, a main casing structure, a detachable part ofsaid structure, a magnet carried by said main structure, pole pieces ofsaid magnet and means for holding said stylus in operating position,said means comprising a metal tube of magnetic material having an innercross-section decreasing towards two radial opposite directions untilbelow the thickness of said stylus for holding said needle in a clampedoperating position, saidmetal tube being arranged between said polepieces to serve as operating armature of said, magnet, a flange of saidmetal tube, at least two sheetsof rubber material carried by saiddetachable part of said main structure, said flange being clampedbetween said rubber sheets.

19. In a pick-up device as described in claim 18, in which elastic meansare arranged between said detachable part andsaidmain casing foradjusting said armature tube to a central position between the polepieces.

In testimony whereof I affix my signature.

STANLEY MoOLATGI-IIE.

